Electric Tankless Help!

My wife and I want to replace our existing water heater with a tankless water heater to free up storage space. Our condo has very little storage space and currently our water heater blocks a huge (relatively speaking) storage space, the area under our stairs. The only way to access that area is to move the water heater and tankless is the best (only?) option. Unfortunately we do not have gas service, only electric. So is it possible to get an electric tankless wh that will supply our whole house (2 BR/2.5BA, DW, WM, etc...) while using multiple applications?

I know that going tankless would involve upgrading the wiring to the water heater which I am prepared to do. What I don't know is A) can my electric service (240 volt) handle a multiple application TWH or would I have to upgrade? How much would that cost? B) What kind of upgrades will I need to make to my electric panel to accommodate the upgraded wiring?

I am new to all this so please go easy on anything that doesn't make sense here... most of it doesn't make sense to me, thatâ€™s why I am turning to this forum.
I appreciate your help!

I would say that you are probably out of luck. Electric tankless units require a large amount of current (Amps). So much that most houses that want to add one will require an upgrade on thier service (how much current capacity that they can pull off the grid). Being in a condo, it is likely that your current service is smaller than a typical house.

1. Go to your panel and see what is says on the main breaker. It should be a number like "150A", "200A", etc. That will tell us what your total capacity is. Given that you don't have gas, I assume that you are on electric heat (baseboards, heat pump, etc.) and probably have AC too.

2. Even if you have enough capacity at the panel, you'll need a much heavier wire from the panel to the WH. The cost would be difficult to say as it depends on access to where the wire needs to be run. Likely, you would have to open up some walls to run the wire and then repair them.

3. If a service upgrade is needed, I'm not sure what will be involved since it is a condo. Likely this would need to be approved from the condo board as you'll need work done in common areas to run the heavier wire to your panel.

You are looking at a significant cost to gain a couple sq ft. I would probably just stay with what you have. However, if you still think it is something you want to look into, see what your panel rating is and list all your major users of electricity (dryer, stove, electric heating/cooling, etc.). This will tell us if the panel/service needs to be upgraded (it almost certainly does). We can go from there.

Thanks nukeman, that really helps. I will take a look at the panel tonight and report back.

In the mean time, another idea I have is to use a storage water heater, but place it under the stairs. At least that opens up the closet that currently houses the WH. I have not measured yet, but I believe I have about 4' clearance under the stair landing, is there a storage heater that will fit in there? I know I would have to move some plumbing and the electric line, but that seems minor in comparison to what I am looking at for the tankless heater.

Thanks nukeman, that really helps. I will take a look at the panel tonight and report back.

In the mean time, another idea I have is to use a storage water heater, but place it under the stairs. At least that opens up the closet that currently houses the WH. I have not measured yet, but I believe I have about 4' clearance under the stair landing, is there a storage heater that will fit in there? I know I would have to move some plumbing and the electric line, but that seems minor in comparison to what I am looking at for the tankless heater.

Click to expand...

There are "lowboy" versions shorter than three feet that you'd likely be able to make work. Go shopping...

For near-tankless efficiency, insulate all of the plumbing (both hot & cold side, and the temperature & pressure outflow plumbing) within 6-10' of the unit with 3/4"-wall closed cell foam pipe insulation (that's twice as thick as the cheap stuff available at big blue or orange box stores. You can order it online if your local supply houses don't have any.) Insulating all of the distribution plumbing helps too- especially if the new location lengthens the plumbing runs.

I think I might have hit a snag with the lowboy\relocation option that I hope someone can help me out with. The current heater sits about 2" away from the floor drain (concrete slab). Can I safely move the heater approx 4' away from the drain or is this going to involve relocating the drain too?

Call Ed Clark at Tankless Concepts. He's in FAirfax. If there is a tankless way, he'll be able to get it done. I doubt electric will work for you. It never hurts to get an opinion from someone in the Biz. He will give you a free estimate one way or the other. If you can somehow get gas, you'll save a fortune also. Get him to have a look.